261828 has 36 divisors (see below), whose sum is σ = 757120. Its totient is φ = 74736.

The previous prime is 261823. The next prime is 261847. The reversal of 261828 is 828162.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (261823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 268 + ... + 771.

2²⁶¹⁸²⁸ is an apocalyptic number.

261828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261828 is an abundant number, since it is smaller than the sum of its proper divisors (495292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261828 is a wasteful number, since it uses less digits than its factorization.

261828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056 (or 1051 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 261828 is about 511.6913131958. The cubic root of 261828 is about 63.9742735141.

It can be divided in two parts, 261 and 828, that added together give a square (1089 = 33²).

The spelling of 261828 in words is "two hundred sixty-one thousand, eight hundred twenty-eight".